Stitch control mechanism for blindstitch sewing machines



Aug. 11, 1964 F. GRECO 3,143,986

STITCH CONTROL MECHANISM FOR BLINDSTITCH SEWING MACHINES Filed March 12, 1962 5 Sheets-Sheet 1 FIG.2

INVENTOR. FRANK GREG O L BY Q Jfi M A TTOR/VEY Aug. 11, 1964 F. GRECO 3,143,986

STITCH CONTROL MECHANISM FOR BLINDSTITCH SEWING MACHINES Filed March 12, 1962 5 Sheets-Sheet 2 INVENTOR. FR/HVK GAECO BY Jp M 4 TTOR/VEY Aug. 11, 1964 F. GRECO 3,143,986

STITCH CONTROL MECHANISM FOR BLINDSTITCH SEWING MACHINES Filed March 12, 1962 5 Sheets-Sheet Z5 llllH FIG. 7

INVENTQR. FRANK GREGG BY 0 Mum g F. GRECO 3,143,986 STITCH CONTROL MECHANISM FOR BLINDSTITCH SEWING MACHINES Aug. 11, 1964 5 Sheets-Sheet 4 Filed March 12, 1962 l j INVENTOR. L,

FP/MK GREGG BY 0 imam M,

ATTORNEY Aug. 11, 1964 GRECQ 3,143,986

STITCH CONTROL MECHANISM FOR BLINDSTITCH SEWING MACHINES Filed Mamh 1962 Y 5Sheets-Sheet 5 2 IIIIIIIIV/ l /A g 54 59 53 65 I FIG. l6

FIG. I?

INVENTOR.

FRANK 6 RE C 0 ATTORNE United States Patent 3,143,986 STITCH CUNTROL MECHANISM FOR BLIND- S'IITCH SEWING MACHINES Frank Greco, Hasbrouck Heights, N.J., assignor, by mesne assignments, to Singer Company of Canada Ltd., Montreal, Quebec, Canada, a corporation of Quebec Filed Mar. 12, 1962, Ser. No. 178,906 1 Claim. (Cl. 112-178) This invention relates to a stitch control mechanism for a blindstitch sewing machine and is applicable to the general desire of users of this type of machine to produce either a skip stitch or a single stitch selectively as desired.

While the reasons for this type of control are well known to those skilled in this art the reader will be briefly apprised of the fact that in certain applications utilizing blindstitch sewing it is preferable to have each stitch engage the cloth while in certain other applications it is desirable to have only each alternate stitch engage the cloth.

With the high cost of labor presently obtaining it is necessary to provide almost instantaneous change from a skip stitch to a single stitch operation in the same machine. If any great amount of down time is required in order to change the stitch control the machine becames clumsy, expensive, inelficient, and unsatisfactory.

It is an object of this invention to produce a stitch control mechanism for a blindstitch sewing machine which Will be rapid and positive in operation and which will involve an insignificant amount of down time.

It is a further object of this invention to provide such a mechanism which can be changed from single stitch to skip stitc operation by means of operation of simple actuating means.

It is a further object of this invention to provide such actuating means which are rapid and foolproof in operation.

It is a further object of this invention to provide a construction which is relatively inexpensive to manufacture, which will require minimum servicing, and which will be simple to operate even for a relatively uneducated workman.

Further objects and advantages of this invention may become apparent to the reader of this specification who.

is presumed to be skilled in this art.

The best mode known to the inventor for carrying out the instant invention is shown in the accompanying drawings which are made a part of this specification. The reader is cautioned, however, to note that the specific structures shown herein are merely for illustrative purposes and for purposes of example only. Various changes and modifications may obviously be made within the spirit and scope of this invention and would occur to those skilled in this art.

The invention will now be specifically described by reference to the accompanying drawings which, as previously mentioned, are made a part of this specification.

FIG. 1 is a front view of a blindstitch sewing machine having the stitch control mechanism of this invention disposed thereupon.

FIG. 2 is a top plan view of the structure shown in FIG. 1.

FIG. 3 is a left side view of the structure shown in FIG. 1.

. FIG. 4 is a fragmentary partial cross-sectional view of the device shown in FIG. 2 taken along line 44 of FIG. 2.

FIG. 5 is a diagrammatic side view showing the manner in which the needle of the blindstitch sewing machine engages the cloth when a normal stitch is produced.

FIG. 6 is a diagrammatic View similar to that of FIG. 5

3,143,986 Patented Aug. 11, 1964 showing the position of the cloth and the needle during the skip stitch action of the machine.

FIG. 7 is a fragmentary top view showing a part of the selectively upwardly movable reciprocating means which operate the ridge forming member and which produce either a single stitch or skip stitch depending upon the position of this member.

FIG. 8 is a sectional view taken along lines 88 of FIG. 7 but also including structure which is broken away from FIG. 7 and not shown in FIG. 7.

FIG. 9 is a sectional view taken along lines 99 of FIG. 7.

FIG. 10 is a sectional view taken along lines 10-10 of FIG. 7.

FIG. 11 is a fragmentary right side view of the machine shown in FIG. 1 but with the driving wheel of the main driving means of the machine removed so as to show the structure therebeneath.

FIG. 12 is a detail perspective view of the push-button means and associated structure which may be optionally utilized to actuate the stitch control mechanism of this invention.

, power the machine.

FIG. 13 is a fragmentary plan view, partly in section, of a portion of a blindstitch sewing machine bearing the stitch control mechanism of this invention.

FIG. 14 is a fragmentary right side detail view showing details of the junction mechanism between the recipr0cating actuating means and the ridge forming member.

FIG. 15 is a plan detail view, partly in section, of the junction mechanism shown in FIG. 14.

FIG. 16 is a sectional view of part of the push-button actuating means taken along lines 1616 of FIG. 12.

FIG. 17 is a right side view, partly in section, of a blindstitch sewing machine including the instant invention.

A full and complete description of the various parts of The blindstitch sewing machine 10, to which the instant: invention is applied, is, with the exception of those p0r-' tions'modified in order to accommodate the invention of this application, of generally conventional construction.

and is basically similar to the construction set forth in the well known Dearborn patents such as United States Patent 2,000,929 and United States Patent 2,064,153. It consists generally of a supporting frame 11 having a main drive shaft 12 disposed thereupon which is secured to drive wheel 13. Drive wheel 13 bears pulley 14 which in turn may be connectable to a driving belt (not shown) so as to Main drive shaft 12 is, by conventional and known construction, operatively connected to reciprocating needle bar 15 which in turn has needle 16 secured thereto by screw 17. Main drive shaft 12 also operates looper 18 and feed mechanism 19. Presser foot gear 22 therebehind. Eccentric 21 reciprocates connecting rod 22a which in turn actuates link 23 and connecting rod 24. Rod 24 is connected to operating member 25' by screw 26. Operating member 25 in turn surrounds upwardly movable turning longitudinal shaft 27 which in, turn bears reciprocatingly projecting ridge forming mem-- ber 28. Ridge forming member 28 is adapted to project through recess 30 within presser foot 20.

The structure hereinafter set forth includes Shaft 27 lies upon longitudinal dished support 31. Support 31 bears a downwardly depending portion 32 and a screw 33 therewithin which is secured into position by nut 34. The assembly of downwardly depending member 32, screw 33 and nut 34 may be considered to be an actuating member for member 31.

Lifting bar 34a bears against screw 33 and is in turn pivotally supported within frame 11 by screw 50. Lifting bar 34a is further connected to rocker shaft 35 by screw 36 which in turn is secured in position by nut 37. Rocker shaft 35 bears an actuating portion 33 at its upper end thereof. A wheel 39 is rotatable upon a shaft 40 secured to rocker shaft 35 below actuating portion 38.

An additional shaft 41 is adjacent shaft 40. A gear 42 is secured to shaft 41 and is held in position by screw 43. An eccentric 44 is also secured to shaft 41 and is normally in abutting relationship with wheel 39.

Rocker shaft 35 is also formed with a projection 45 and frame 11 bears a projection 46 spaced from projection 45. A spring 47 is disposed across projections 45-46 and normally holds Wheel 39 of rocker shaft 35 against eccentric 44. Spring 47 also permits the return of rocker shaft 35 to its normal position when it is displaced therefrom by the operation of the stitch control mechanism as will be subsequently explained.

Lifting bar 34a bears an upwardly extending portion 48 having an abuttable portion 49 thereupon. Portion 49 abuts screw 33 of support 31.

Support 31 also bears an additional downwardly depending portion 51 thereupon and an additional adjacent downwardly depending portion 52 is also provided. A spring 53 extended between portions 51 and 52 causes portion 49 of lifting bar 34a to remain in abutting relationship with screw 33 of support 31.

Forwardly movable first actuator 54 is disposed within a recess within frame 11. A tube 55 is disposed within the recess within frame 11 and first actuator 54 slides within tube 55. Actuator 54 bears a projection 56 thereupon which is slidably movable within cut-out portion 57 within tube 55. A push button 58 is secured to actuator 54 at one end thereof and a projecting member 59 is secured to actuator 54 at its opposite end. Actuator 54 passes through an opening within downwardly depending member 59 and is held in position by nut 60 which is threadedly connected to the end portion of actuator 54.

A spring 61 is disposed upon actuator 54 and normally holds actuator 54 in rearward position.

Actuator 54 also bears a transverse recess 62 there- Within. A holding member 63 is selectively disposable within recess 62. Holding member 63 bears a projection 64 and an adjacent projection (not shown) is disposed in spaced relationship therewith upon frame 11 of the machine. A spring 65 extends between projections 64 and its adjacent projection and holds holding member 63 within recess 62 when required.

Actuator 54, as stated before, is forwardly movable so that holding member 63 will snap into recess 62 as will be subsequently explained.

Holding member 63 is pivotally movable about screw 66.

An additional actuator 67 is disposed upon frame 11 within tube 68 and bears a reduced cross-sectional area 69 at its forward end. A push button 70 is disposed at the opposite end of actuator 67. A spring 71 is disposed upon actuator 67 and normally holds actuator 67 in rearward position.

With the foregoing description the operation of this invention will now be explained.

In the normal position of the parts of the machine first actuator 54 is in forward position and downwardly depending member 59 does not control rocker shaft 35. When drive wheel 13 is rotated gear 22 rotates and eccentric 21 reciprocates connecting rod 22a which in turn re ciprocates member 27 and selectively causes ridge forming member 28 to move within recess 30. At the same time main drive shaft 12 reciporcates needle bar 15 so that stitches are made.

The above movements also rotate gear 42 and thus power eccentric 44 which, since it is in abutting relationship with wheel 39 which in turn is connected to rocker shaft 35, causes rocker shaft 35 to periodically pivot and thus, at certain times, rocker shaft 35 causes lifting bar 34a to rotate which in turn rotates support 31 and which in turn raises member 27.

The device is so constructed that when member 27 is in upward position ridge forming member 28 will project sufficiently through opening 36 in presser foot 20 to permit needle 16 to pass through the work as shown in FIG. 5. However, when member 27 is in downward position ridge forming member will not project sufficiently to permit needle 16 to pass through the work as shown in FIG. 6. This produces, what is called a skip stitch. The timing of the parts is so performed that, in the normal position mentioned above, member 27 is in upward position for one stitch and in downward position for the following stitch.

If button 58 is pushed actuater 54 moves in and downwardly depending portion 59 pushes rocker shaft 35 rearwardly. Holding member 63 snaps into recess 62 so that actuator 54 is held in forward position. In this position eccentric 44 is out of contact with wheel 39 and member 27 is held in upward position. Thus only single stitches are produced.

When it is again desired to set the machine for its normal action button 70 is pressed causing actuator 67 to move inwardly. This raises holding member 613 out of recess 62 and causes actuator 54 to snap back thus again Setting the machine for normal operation.

The foregoing specific embodiments of this invention as set forth in the specification herein are for illustrative purposes and for purposes of example only. Various changes and modifications may obviously be made within the spirit and scope of this invention and would occur to those skilled in this art.

I claim:

In a blindstitch sewing machine having main driving means, a reciprocatingly projecting ridge forming member, stitch forming means including needle means, cloth feeding means, and a selectively upwardly movable turning longitudinal shaft for actuating said ridge forming member, all operatively connected to said main driving means;.the improvement which comprises a longitudinal dished support disposed beneath said longitudinal shaft, a pivotally movable lifting bar operatively related to said dished support, a rocker shaft secured to said lifting bar, an eccentric disposed against said rocker shaft, a first gear secured to said eccentric, and a second gear meshing with said first gear and also secured to said main driving means, means operatively connected with said lifting bar normally causing upward movement of said support during alternate periods of reciprocation of said ridge forming member so that a skip stitch is produced, said means operatively connected with said lifting bar also adapted to lock said lifting bar in upward position so that a single stitch is produced, said means operatively connected with said lifting bar comprising a forwardly movable first actuator having a projecting member secured thereto and normally in spaced relationship with said rocker shaft, a recess within an intermediate portion of said first actuator, first push-button means carried by said supporting frame operatively connected with said first actuator, first spring means upon said first actuator adapted to hold said first actuator in normal position, a pivotally movable holding member in abutting relationship with said first actuator, second spring means operatively connected with said holding member and normally maintaining said holding member against Said first References Cited in the file of this patent UNITED STATES PATENTS Eichenauer June 2, 1931 Horni June 16, 1931 Dearborn May 14, 1935 Rivers Apr. 7, 1936 Matthews et al Feb. 11, 1941 Parry May 6, 1958 FOREIGN PATENTS France Jan. 11, 1960 

